• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.91-98
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• 2006

A light guide panel (LGP) is an element of the LCD back light unit, which is used for display devices. In this study, the laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected. A Web-based design tool was developed to generate patterns of light guide panel at any location, and the tool may assist the designer to develop optimized patterns. Topcon-BM7 was used for luminance measurement of each specimen with $100mm{\times}100mm$ area. By Taguchi method optimized levels of each parameters were found, and luminance of $3523cd/cm^2$ and uniformity of 92% were achieved using the laser machined BLU.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.404-407
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• 2004

This Research suggested direction of development and analyzed necessity and given condition of CM(Construction Management) operation system of SOC private infrastructure project which is judged to grow up continuously from now on, Direction of development which is suggested in this research is largely there, (1)development of SOC private infrastructure project CM work standard process guide, (2)development of SOC Private Investment project feasibility study Performance standard, (3)checklist of SOC by stages and functionally private investment projects risk. Through this development, later we judge effect not only supply of a model case to artivate CM system but heightening of efficiency in domestic construction industry.

• Tunnel and Underground Space
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• v.21 no.3
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• pp.235-243
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• 2011

In this study, a control blast method, which utilizes crack guide holes, is suggested to achieve smooth fracture plane and minimize blast damage zone (BDZ) in smooth blasting. In order to verify the effectiveness of crack guide holes on the fracture plane control in blasting, fracture process analyses which consider regular smooth blasting and guide hole smooth blasting had been conducted and the fracture planes resulting from the analyses had been compared. The analyses models considered the ignition of the blast holes using detonation cords and each guide hole placed between blast holes. From the results, the smooth blasting utilizing guide holes showed lower fracture plane roughness than regular smooth blasting method in the hole spacing range between 20 to 40cm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.105-108
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• 1995

So far,in deep drilling process there are several manufacturing problems such as hole deviation, hole over size, circularity,straightness and surface roughness. Whit regard to these problems, we atudied the abrasion process on carbided tip of BTA drill and got the follow test results through the abrasion characteristic test and analysis on cutting mechanism for the drill tooth and guide pad. 1) In SM55C drilling process, the most stable and reasonable drilling speed range for optmum abrasion characteristic of drill tooth was 60m.min. 2) The total drilling torque was about 60kg .deg.cm on condition drilling speed 60m/min and 0.15mm/rev. These results show that the theoretical burnising torque is well accord with the tested torque which is working on guide pad.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.133-143
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• 2013

BIM can be utilized variously in construction management(CM) in the respect that it helps to manage comprehensively the construction information and make reliable decisions, but the adoption of BIM is insufficient in the CM area. The purpose of this study is to develop work process models and their guides in order to utilize BIM effectively in CM work at construction stage. This study defined BIM functions as 'BIM converting design', 'Model review', 'Data extraction', 'Automatic estimate', '4D simulation', 'Drawing creation', 'Engineering sector linkage analysis' through literature search, and generated CM works applicable to BIM by analyzing the CM work and process. This study developed BIM-based CM work process models by reconstructing the existing work process in connection with BIM function through an analysis on the relationship between BIM function and CM work, and reconstructing the role of each project participants. In order to improve the usefulness of the developed models, guides that described the BIM works of project participants were prepared through interviews and case studies. To validate the utilization of the models, a comparative analysis on the BIM process of precedent studies was also made and a survey was conducted on experts. This study can contribute to increasing the utilization of BIM in the CM area and can be helpful for CM companies to develop an in-house BIM guide. In the future, it will be necessary to make an assessment on the models from a business perspective through case applications and constantly update BIM-based CM work process model in consideration of the expansion of CM work due to the application of BIM.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.620-624
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• 2004

The Construction Industry become to large. So, construction management is needed. In Korea, an organic law about construction industry was made in 1996. And CM was introduced, too. But CM is not activated with institutional inertia. A reason Is a perpetual friction between CM and Gamri. And it is not thoroughgoing enough about supply of CM's effect with Chf Best Practice checklist and Key Performance Index. This study will develop the CM Best Practice checklist with CM's work and technique in project-dimensional. The CM Best Practice checklist will guide to have a good result.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.9
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• pp.795-800
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• 2008

A sublimation method using the SiC seed crystal and SiC powder as the source material is commonly adopted to grow SiC bulk single crystal. However, it has proved to be difficult to achieve the high quality crystal and the process reliability because SiC single crystal should be grown at very high temperature in closed system. The present research was focused to improve SiC crystal quality grown by PVT method through using the new inner guide tube. The new inner guide tube was designed to prevent the enlargement of polycrystalline region into single crystalline region and to enlarge the diameter of SiC single crystal. The 6H-SiC crystals were grown by conventional PVT process. The seed adhered on seed holder and the high purity SiC source materials are placed on opposite side in sealed graphite crucible surrounded by graphite insulation. The SiC bulk growth was conducted around 2300 $^{\circ}C$ of growth temperature and 50 mbar in an argon atmosphere of growth pressure. The axial thermal gradient across the SiC crystal during the growth was estimated in the range of 15${\sim}$20 $^{\circ}C$/cm.

• The Korean Journal of Pain
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• v.13 no.1
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• pp.93-96
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• 2000

Background: Psoas compartment block with local anesthetics and corticosteroids is one of the treatments which provides long term analgesia of the lower back and anterior thigh unilaterally, and its technical easiness and safety allows blind application without C-arm guidance in the out-patient clinic. This study aimed to evaluate the mean of the depth from the skin to the psoas compartment, and its correlation to the following attributes: age, weight, height and PI (Ponderal Index). Methods: We investigated 28 patients who underwent psoas compartment block. All blocks were performed using Chayen's method (punctured at the point of 3 cm caudally and 5 cm laterally from the 4th lumbar vertebral spinous process) with a 22 G, 8 cm Tuohy needle under C-arm guidance. We recorded the depth from skin to the psoas compartment, height, weight and PI (weight (kg)/height (cm)$\times100$ (%)). Data were analyzed using the Pearson product-moment correlation coefficients. The correlations between the depth and other attributes identified by p-value of less than 0.05 were considered statistically significant. Results: The mean depths from skin to the psoas compartment were $6.02{\pm}0.28$ cm in men, $5.44{\pm}0.22$ cm in women. There is no significant correlation between the depth and other patient's attributes. Conclusions: The mean depths from skin to the psoas compartment may be one of the guide for psoas compartment block in outpatient clinics without C-arm guidance.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.107-118
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• 2008

The XP, the representative methodology of Agile software development, maximizes the effectiveness of the development by focusing on development itself and using primitive and basic process definition that can be easily implemented in the fields. However, the most of XP's practices came from those of engineering and the manogement practices of work product tend to be overlooked. The research on the implementation of those manogement practices has not been performed enough. Because of deficiency of processes that guide the change control over major baselines of work product and that describe proper continuous integration and refactoring in XP, the integrity of those work products is difficult to be guaranteed. To fulfill this work product integrity, CM(configuration manogement) should be hired and CMMI(Capability Maturity Model Integration) is considered to be the best references for that purpose, CMMI defines the required practices of CM and leave implementation details to the organization so that it could customize those practices based on the characteristics of its development methods. The CM process implementation guidelines based on CMMI could provides work product integrity with a way of keeping XP's agility that includes continuous integration, refactoring and small release. In this research, we selected CM process factors applicable to XP among CMMI's CM practices and based on them we developed the CM implementation guidelines.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.87-95
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• 2013

The number of construction management firms has been increased as construction management delivery system has been active in Korean construction market. the capability of leading construction management professional, who is responsible for managing project administration, is important for commissioning construction management contracts. The quality of project proposal and the capability of leading construction management professional, which are assessed by the board of contract awarding committee, are the major contributors for commissioning the public construction management projects administered by the Korean public procurement service for contracting. Therefore, employing a very competent leading construction management professional is the critical strategy for awarding contract to the construction management firms' part. That is why the firms should secure a fixed number of leading construction management professional in a waiting list to proceed the contract commissioning process for expectant candidate projects, even if there is no project assignable to the leading construction management professionals. However, a measure that makes effectively use of the leading construction management professional in a waiting list has not been systematically implemented in the firms. In turn, the firm suffers considerable loss in a project personnel supply and demand plan. Expert opinions were obtained by the survey questionaries administered to top management of the construction management firms which are engaged in the construction management contracts for commissioning the public construction management projects administered by the Korean public procurement service either as principal or co-principal deliverer. This paper presents the findings obtained by investigating the actual employment state of the leading construction management professional in the waiting list and by analyzing the issues involved in mobilizing and demobilizing them. It contributes to implement a practical guide for searching effective solutions to the issues.